A dishwasher is a home appliance that washes dishes by discharging high-pressure wash liquid through discharge members onto the dishes to remove impurities thereon.
In more detail, a dishwasher includes a tub forming a space inside the dishwasher for holding dishes to be washed, dish racks installed to slide in and out of the tub for holding dishes, discharge members installed inside the tub for spraying wash liquid, a sump disposed at the bottom of the tub for holding wash liquid, a wash pump assembly attached to a side of the sump for pumping the wash liquid contained in the sump to the discharge members, and a drain pump assembly for draining dirty wash liquid after dish washing is completed.
The discharge members consist of a lower arm installed above the sump, and an upper arm and a top nozzle connected to a water guide installed on an interior surface of the tub. Wash liquid is alternately pumped to the lower arm and the water guide by means of a switching valve located in the sump. In other words, during a wash cycle, the wash liquid that is alternately pumped by means of the switching valve is intermittently pumped at a predetermined interval to the lower and upper arms.
A conventional dishwasher generally activates a heater for heating wash liquid while the wash pump is operating during a hot rinse cycle. In other words, while the rinse cycle is underway, the heater heats the wash liquid to gradually warm it.
When the heating of the wash liquid and the pumping thereof are simultaneously implemented, wash liquid that has not yet reached a preset temperature is discharged from discharge members. Also, when the discharged wash liquid re-enters the sump, heat is lost, so that the wash liquid takes a long time to be heated to a preset temperature.